Combination hydraulic motor driven hydraulic pump and air compressor assembly

ABSTRACT

A hydraulic pump driven by a reaction motor energized by pressurized fluid, in one application, from a vehicle power steering system. The hydraulic motor includes a reaction rotor driving a pump rotor. Hydraulic fluid is pressurized by the pump and applied against one side of a diaphragm air compressor. The diaphragm responds to inlet and discharge pulses in the hydraulic pump pressurizing air in a chamber on the other side of the diaphragm. Inlet and exhaust valves are associated with the air pressurizing chamber regulating flow of inlet air into and discharge of pressurized air out of the chamber during cyclic operation of the pump. In preferred form; the motor, pump and diaphragm compressor are incorporated into an integral unit and air pressurized by the compressor is supplied to a vehicle leveling system.

United States Patent Jackson COMBINATION HYDRAULIC MOTOR DRIVENHYDRAULIC PUMP AND AIR COMPRESSOR ASSEMBLY George W. Jackson, Dayton,Ohio General Motors Corporation, Detroit, Mich.

Filed: Apr. 28, 1972 Appl. No.: 247,325

Inventor:

Assignee:

References Cited UNITED STATES PATENTS Vlachos 417/406 X Hartmann et a1417/390 Primary Examiner-Carlton R. Croyle Assistant Examiner-RichardShek Attorney-Frank J. Soucek and Charles R. Engle 5 7] ABSTRACT Ahydraulic pump driven by a reaction motor energized by pressurizedfluid, in one application, from a vehicle power steering system. Thehydraulic motor includes a reaction rotor driving a pump rotor.Hydraulic fluid is pressurized by the pump and applied against one sideof a diaphragm air compressor. The diaphragm responds to inlet anddischarge pulses in the hydraulic pump pressurizing air in a chamber onthe other side of the diaphragm. Inlet and exhaust valves are associatedwith the air pressurizing chamber regulating flow of inlet air into anddischarge of pressurized air out of the chamber during cyclic operationof the pump. in preferred form; the motor, pump and diaphragm compressorare incorporated into an integral unit and air pressurized by thecompressor is supplied to a vehicle leveling system.

3 Claims, 8 Drawing Figures Patented Aug. 21, 1973 3,753,629

2 Sheets-Sheet l COMBINATION HYDRAULIC MOTOR DRIVEN HYDRAULIC PUMP ANDAIR COMPRESSOR ASSEMBLY This invention relates to a combined assemblyincluding a hydraulic reaction motor driving a hydraulic pump which inturn actuates a diaphragm air compressor. More specifically, thisinvention relates to such a combination receiving pressurized hydraulicfluid from a vehicle power steering system and actuating a diaphragmcompressor supplying pressurized air to an automatic vehicle levelingsystem.

Provision of compressed air in automatic vehicle leveling systems has,in the past, necessitated use of electrically powered or vehicle enginepowered compressors. The structure of this invention results in a moreefficient method of providing a source of compressed air required in anautomatic vehicle leveling system by using an existing supply of fluidunder pressure. The combination hydraulic motor, pump and diaphragm aircompressor of this invention could, of course, be used in anyenvironment where a source of pressurized hydraulic fluid is availableto energize the hydraulic reaction motor. The hydraulic pump receivesand pressurizes fluid for application against one side of the diaphragmair compressor. The diaphragm is responsive to the suction or inletfluid cycle of the pump on one side thereof and draws air into an airchamber on the other side of the diaphragm during the inlet cycle.During the pump pressure cycle, pressurized fluid is transmitted throughappropriate passages to the fluid side of the diaphragm moving it todecrease the volume of the air chamber, pressurizing air therein andforcing it through an exhaust valve to either a pressure supply tank ordirectly to a vehicle leveling system as conditions of the system mayrequire. Since the combined unit of this invention utilizes pressurizedfluid from an existing system for the energization thereof, thenecessity of providing an additional power source is eliminated therebyalso eliminating the consequent added inefficiencies associated with anadditional power source.

Accordingly, a first object of this invention is the provision of ahydraulic reaction motor, a hydraulic pump and a diaphragm aircompressor as a single unit reducing the number of required componentsto a minimum while eliminating plumbing therebetween.

Another object of this invention is the provision of a hydraulicreaction motor receiving pressurized hydraulic fluid from a vehiclepower steering system driving a hydraulic pump cycling a diaphragm aircompressor.

A further object of this invention is the provision of a hydraulicreaction motor responding to pressurized hydraulic fluid from anexternal source driving a hydraulic pump pressurizing fluid andproviding means for applying the pressurized fluid against a diaphragmair compressor for supplying pressurized air to an automatic vehicleleveling system.

These and other objects will be more apparent from the followingdetailed description of a preferred embodiment of my invention taken inconnection with the accompanying drawings wherein:

In the drawings:

FIG. 1 is an end plan view of the subject hydraulic reaction motor,hydraulic pump and diaphragm air compressor assembly;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 2;

FIG. 5 is a fragmentary cross-sectional view taken on line 5-5 of FIG.1;

FIG. 6 is a fragmentary cross-sectional view taken on line 6-6 of FIG.4;

FIG. 7 is an end plan view of the air compressor valve plate of thesubject invention; and

FIG. 8 is an enlarged fragmentary cross-sectional view taken on line 8-8of FIG. 7.

With reference to FIG. I, the hydraulic reaction motor, pump anddiaphragm air compressor assembly 10 of my invention is shown in endplan view. As best shown in FIG. 2, the assembly 10 includes a housing12 having a removable end plate 14 and an integral end plate 16, theremovable end plate 14 being secured to the housing 12 by a plurality ofthreaded bolts 18. The end plate 14 is formed including an annularflange 20 while the end plate 16 is formed including a similar annularflange 22 providing journal bearing surfaces 21 and 23, respectively,receiving a stationary shaft 24. An annular groove 27 is provided in theend plate 14, adjacent housing 12 and transfer plate 28, and receives anO-ring seal 29 preventing leakage of fluid exteriorly of the housing. Asplined sleeve 26 is free to rotate on the exterior surface of shaft 24and extends between the flanges 20 and 22 of the end plates for rotationtherebetween. A transfer plate 28 is concentrically received upon theflange 20. A first porting plate 30 is also positioned upon the flange20 in contact with the transfer plate 28 for a purpose later to bedescribed. An annular stator 32 is received within housing 12 adjacentthe first porting plate 30 and has its outer circumferential surface infixed engagement with the housing 12. A fluid reaction rotor 34, havingan internally splined opening 36, shown in FIG. 3, is mounted on thesplined sleeve 26 for rotation therewith. The rotor 34 is positioned torotate within the stator 32. A second porting plate 38, a mirror imageof the plate 30, is positioned adjacent stator 32 and the fluid reactionrotor 34. The porting plates, stator and reaction rotor, all cooperateforming a fluid motor assembly as is well known in the art.

A pump stator 40 is also retained within the housing 12 in fixedrelationship therewith and is positioned in engagement with end plate16. A pump rotor 42 contains a splined opening 44, similar to opening 36in reaction rotor 34, and likewise is received upon the sleeve 26 forrotation on stationary shaft 24. The pump stator 40 and rotor 42cooperate forming a pump assembly discharging pressurized fluid througha passage 46 in integral end plate 16 and an opening 47 in a fluidcontrol plate 49 to a fluid chamber 48 on one side of an air compressordiaphragm 50. An air pressurizing chamber 52 is defined on the otherside of the diaphragm 50 by the diaphragm and a machined portion 54 inan air valve plate 56. The air valve plate 56 is secured to the integralend plate 16 by a plurality of screws 58 as shown. A metal diaphragmback-up plate 60 containing apertures 62 is retained between the airvalve plate 56 and end plate 16 by the screws 58. An air inlet valve 64includes an annular flange 66 received in a recess 68 in the valve plate56. The valve 64 extends through an aperture 70 in plate 56 and isretained therein by a spring 71 engaging an annular valve groove 72. Theair valve plate 56 is cast or otherwise formed to include an annularrecess 74 having a deformable lip 76 therearound. A valve cover andconduit assembly 78 is received in the recess 74 and is retained thereinby crimping the lip 76 against flanges 80 of the cover and conduitassembly 78.

As is best illustrated in FIG. 3, the fluid reaction rotor 34 contains aplurality of radially extending slots 82 receiving springs 84 biasingvanes 86 outwardly against the inner circumferential surface 88 ofstator 32. The rotor 34 and its slidable vanes 86 receive pressurizedfluid from the vehicle power steering system through a supply passage 90causing rotation of the rotor clockwise as viewed in FIG. 3. The fluidis discharged from rotor stator chamber 92 through a passage 94 where iteventually returns to the power steering system, not shown.

Referring now to FIG. 4, the pump rotor 42 includes the previouslymentioned plined opening 44 by which it is also received upon the sleeve26 for rotation on stationary shaft 24. The rotor 42 is eccentricallymounted with respect to an opening defined by inner surface 96 of stator40. The stator 40 contains diametrically opposed radially extendingslots 98 receiving slidable vanes 100. The stator 40 is ported such thatpressurized fluid is continuously applied to chambers 102 on the outersides of the vanes 100 continuously urging them into engagement withouter surface 104 of the rotor. Inner surface 96 of stator 40 and outersurface 104 of pump rotor 42 define a fluid inlet non-pumping chamber106 above the diametrically oppositely positioned vanes 100 and asimilar chamber 108 in the lower half of the structure which is in fluidconnection with passages 46 which supplies pressurized fluid to andwithdraws fluid from chamber 48 on the upper side of diaphragm 50 asshown in FIG. 2. The non-pumping chamber 106 is connected to an outletI17 returning fluid to the power steering sump.

With reference to FIG. 5, a portion of the removable end plate 14 isshown including a boss formed thereon, the latter containing acylindrical machined cavity 150. A pressure relief valve 112 is placedin the cavity 150 and is biased by a spring 114 against a valve seat 116normally blocking flow through aperture 118 in transfer plate 28. Againreferring to FIGS. 1 and 2, pressurized inlet fluid is received from thepower steering system via port 113 in end plate 14 and enters an annularpassage 115 in the transfer plate 28. The pressurized fluid is appliedagainst valve 112, which opens to return the fluid to the power steeringsystem sump through outlet 117 in FIG. 1 upon the occurrence ofexcessive inlet pressure. As previously mentioned, outlet 117 alsoconducts flow from chamber 106 to the sump. The purpose of the valve 112 therefore, is to prevent high fluid pressure damage to the subjectassembly should the reaction motor, hydraulic pump and diaphragmcompressor assembly stall for some reason such as a bearing failure.Utilization of the valve 112 bypasses the assembly under thesecircumstances without interferring with the normal operation of thepower steering system.

In FIG. 6, a valve 120 is biased into engagement with a valve seat 122in plate 49 by a spring 124. The valve 120 is in fluid connection withdiaphragm air compressor fluid chamber 48 via a passage 126. Valve 120is operative to limit the maximum air pressure supplied by the diaphragm50 by virtue of its limiting the pressure of the oil supplied directlyagainst the diaphragm as will be later explained. This feature isaccomplished by the valve responding to excess pressure and exhaustingfluid into chamber 121 from which the fluid flows through passage 123 inshaft 24 to port 125 which connects with a conduit to a hydraulic fluidreservoir, not shown.

Referring now to FIGS. 7 and 8, the air valve plate 56 includes thevalve cover and conduit assembly 78 which is retained by thecrimped-over rim 76. The plate 56 also includes an axially extendingboss 128 threadably receiving a plug 130 retaining a spring 132 biasingan exhaust valve 134 closed against a valve seat 136. The valve 134 isoperative to close an air exhaust passage 138. An angularly extendingboss is also formed on the air valve plate 56 and threadably receives afitting 142 connecting with an angularly extending passage 144 in fluidconnection with passage 138 when exhaust valve 134 is opened. Thefitting 142 is connected with a supply line, not shown, to conveypressurized air to vehicle lift units in an automatic vehicle levelingsystem, also not shown.

In operation, pressurized fluid from the vehicle power steering systementers passage 113 in end plate 14 and flows into chamber 115 intransfer plate 28. Transfer plate 28 and the porting plate 30 direct thefluid through aperture 31 into aperture 33 in stator 32 wherein it isguided by passages, not shown, and applied against vanes 86 rotatingreaction rotor 34 in a clockwise direction.

Clockwise rotation of the reaction rotor 34 rotates splined sleeve 26 onthe shaft 24 driving pump rotor 42 within stator 40. The eccentricrotation of rotor 42, while being continuously engaged by the fluidbiased vanes 100, causes pressurization of fluid in chamber 108 due tothe space between the rotor and the stator decreasing in the lower halfof the assembly in FIG. 4. The pressurized fluid exits chamber 108 andflows through passages 46 and 47, in end plate 16 and valve plate 49,respectively, into fluid chamber 48 on the upper side of diaphragm 50,best shown in FIG. 2.

The diaphragm 50 is responsive to the inlet and pressurizing cycles ofthe pump rotor 42 and accordingly is raised to increase the volume anddraw air into chamber 52 through valve 64 during the inlet cycle and islowered to decrease thevolume pressurizing air during the pump fluidpressurizing cycle. Hydraulic fluid is supplied to chamber 48 throughmake-up valve 35 so as to maintain the chamber filled. It is necessarythat the chamber 48 be completely filled so that the air diaphragm 50will be fully responsive to the pressure pulses from the hydraulic pumpassembly including the stator 40 and rotor 42. The chamber 52 anddisplacement of pump rotor 42 into chamber 108 are sized so thatdiaphragm 50 bottoms in chamber 52 assuring positive pressurization ofthe air therein. The hydraulic relief valve 120, shown in FIG. 6,prevents excessive pressure being applied to the diaphragm 50 byexhausting fluid into chamber 121, FIG. 6, when a predetermined pressureis exceeded.

It has been found that a vehicle power steering system employing an opencenter control valve will in its neutral valve position be circulatinghydraulic fluid in a pressure range of 45-75 psi. In a slow vehiclespeed turn or during a parking maneuver wherein the control valve ismoved closed, pressure of fluid in the system may be as high as 500-600psi. Maximum fluid pressure is obtained if a wheel engages a curb or alike fixed object, this pressure being 1,000 psi. Normal vehicle useresults in fluid pressures in the range of 100-500 psi depending uponvehicle speed and angle of turning.

My invention, as described above, is designed to ac commodate all ofthese conditions. By including the pressure relief valve 1 12, thecombined reaction motor, fluid pump and air compressing diaphragm 50 canaccommodate all operational extremes, including the range of fluidpressures, of the power steering system while efficiently storing ordirectly supplying pressurized air to the automatic vehicle levelingsystem.

While I have shown and described a specific embodiment of the presentinvention it will, of course, be understood that alternative forms maybe provided without departing from the scope thereof. 1, therefore,intend by the appended claims to cover all such modifications andalternative constructions falling within their definitive scope.

I claim:

1. A mechanism to compress air oil free from a source of oil underpressure, comprising; a housing having a cylindrical bore, saidcylindrical bore having a first closed end, a first stator secured insaid bore adjacent said first closed end, a fluid motor comprising afirst rotor rotatably disposed within said first stator, a second statorin said bore and a second rotor cooperable with said second stator anddefining in conjunction therewith a fluid pump having a pulsatingaction, means defining a second closed end of said bore opposite to saidfirst closed end and adjacent the pump, plate means secured to saidhousing at said second closed end forming a cavity between said housingand said defining means, a diaphragm dividing said cavity into a fluidchamber and an air chamber, and valve means in said plate meansresponding to the pulsating action of fluid from said pump applied toone side of said diaphragm in the fluid chamber whereby air is drawninto the air chamber of said cavity on the other side of said diaphragmduring the intake cycle of said pump and said diaphragm moves inresponse to the pulsating action of said pump compressing the air duringthe pressure discharge cycle of said pump.

2. A mechanism to compress air oil free from a source of oil underpressure, comprising; a housing having a cylindrical bore defining anintegral flat face at one end of said bore, an end plate secured to saidhousing at the other end of said bore closing the same, said flat faceand said end plate both including axially extending flanges definingaxially extending cylindrical cavities, a shaft fixedly mounted in saidcavities of said flat face and said end plate flanges, a sleeve memberrotatably received upon said stationary shaft, a pump stator fixed insaid housing adjacent said integral flat face, a pump rotor secured tosaid sleeve for rotation therewith within said stator thereby forming apump assembly, a reaction motor stator secured in said housing, areaction motor rotor secured to said sleeve for rotation therewithwithin said stator forming a motor assembly, a fluid directing platedisposed between said end plate and said reaction motor assembly, meansin said end plate receiving pressurized fluid from an external sourceand directing the same through said fluid directing plate to drive saidreaction motor rotor and said pump rotor, a diaphragm air compressorassembly defining a diaphragm receiving cavity attached to said integralflat face, a diaphragm in said cavity, fluid from said pump beingapplied to one side of said diaphragm, and valve means in said aircompressor assembly providing for the inlet of air into said cavity onthe other side of said diaphragm when said pump is operating in itsintake cycle and discharging pressurized air from said cavity when saidpump is in its pressurized cycle.

3. A mechanism to compress air oil free from a source of oil underpressure, comprising; a housing having a cylindrical bore having anintegral closed end defining a flat face, a removable end plate securedto said housing at the other end of said bore closing said bore, annularflanges extending axially from each of said housing ends definingaxially extending cylindrical cavities, a shaft fixedly mounted in saidannular flanges, a sleeve rotatably mounted upon said stationary shaft,a valve plate secured to said integral closed end defining a diaphragmreceiving cavity therebetween, a diaphragm in said cavity dividing thesame into a fluid chamber on one side of said diaphragm and an airchamber on the other side of said diaphragm, an air inlet valve in saidvalve plate, an air exhaust valve in said valve plate, a pump statorsecured in said housing adjacent said integral closed end, a pump rotorfixed on said sleeve for rotation therewith within said pump statorforming a pump assembly, at least one vane slidably mounted in a slot insaid pump stator and biased into engagement with the outercircumferential surface of said pump rotor by fluid pressure supplied tothe slot, said pump having a pulsating action, a porting plate securedin said housing adjacent said pump assembly, a reaction motor statorsecured in said housing adjacent said porting plate, a reaction motorrotor fixed to said sleeve for rotation within said motor stator, aplurality of axially extending slots circumferentially spaced in theouter periphery of said rotor, a spring biased vane slidably received ineach of said slots and engaging the inner circumferential surface ofsaid motor stator, said reaction motor stator and rotor forming a motorassembly, a second porting plate secured in said housing adjacent saidmotor assembly, a fluid directing plate positioned on said annularflange of said end plate between said second porting plate and the endplate, means in said end plate, said fluid directing plate and saidporting plates supplying pressurized fluid from an external sourcedriving said reaction motor assembly rotating said sleeve driving saidpump assembly, the latter supplying pressurized fluid pulses to saidfluid chamber on one side of said diaphragm whereby the diaphragmresponds to inlet conditions in said pump and draws air into said airchamber through said inlet valve and responds to fluid pressurizingconditions in said pump and compresses air in said air chamberdischarging it through said exhaust valve, and a pressure relief valvein said end plate opening to bypass flow of fluid from the externalsource when the pressure of such fluid exceeds a safe operating range.

1. A mechanism to compress air oil free from a source of oil underpressure, comprising; a housing having a cylindrical bore, saidcylindrical bore having a first closed end, a first stator secured insaid bore adjacent said first closed end, a fluid motor comprising afirst rotor rotatably disposed within said first stator, a second statorin said bore and a second rotor cooperable with said second stator anddefining in conjunction therewith a fluid pump having a pulsatingaction, means defining a second closed end of said bore opposite to saidfirst closed end and adjacent the pump, plate means secured to saidhousing at said second closed end forming a cavity between said housingand said defining means, a diaphragm dividing said cavity into a fluidchamber and an air chamber, and valve means in said plate meansresponding to the pulsating action of fluid from said pump applied toone side of said diaphragm in the fluid chamber whereby air is drawninto the air chamber of said cavity on the other side of said diaphragmduring the intake cycle of said pump and said diaphragm moves inresponse to the pulsating action of said pump compressing the air duringthe pressure discharge cycle of said pump.
 2. A mechanism to compressair oil free from a source of oil under pressure, comprising; a housinghaving a cylindrical bore defining an integral flat face at one end ofsaid bore, an end plate secured to said housing at the other end of saidbore closing the same, said flat face and said end plate both includingaxially extending flanges defining axially extending cylindricalcavities, a shaft fixedly mounted in said cavities of said flat face andsaid end plate flanges, a sleeve member rotatably received upon saidstationary shaft, a pump stator fixed in said housing adjacent saidintegral flat face, a pump rotor secured to said sleeve for rotationtherewith within said stator thereby forming a pump assembly, a reactionmotor stator secured in said housing, a reaction motor rotor secured tosaid sleeve for rotation therewith within said stator forming a motorassembly, a fluid directing plate disposed between said end plate andsaid reaction motor assembly, means in said end plate receivingpressurized fluid from an external source and directing the same throughsaid fluid directing plate to drive said reaction motor rotor and saidpump rotor, a diaphragm air compressor assembly defining a diaphragmreceiving cavity attached to said integral flat face, a diaphragm insaid cavity, fluid from said pump being applied to one side of saiddiaphragm, and valve means in said air compressor assembly providing forthe inlet of air into said cavity on the other side of said diaphragmwhen said pump is operating in its intake cycle and dischargingpressurized air from said cavity when said pump is in its pressurizedcycle.
 3. A mechanism to compress air oil free from a source of oilunder pressure, comprising; a housing having a cylindrical bore havingan integral closed end defining a flat face, a removable end platesecured to said housing at the other end of said bore closing said bore,annular flanges extending axially from each of said housing endsdefining axially extending cylindrical cavities, a shaft fixedly mountedin said annular flanges, a sleeve rotatably mounted upon said stationaryshaft, a valve plate secured to said integral closed end defining adiaphragm receiving cavity therebetween, a diaphragm in said cavitydividing the same into a fluid chamber on one side of said diaphragm andan air chamber on the other side of said diaphragm, an air inlet valvein said valve plate, an air exhaust valve in said valve plate, a pumpstator secured in said housing adjacent said integral closed end, a pumprotor fixed on said sleeve for rotation therewith within said pumpstator forming a pump assembly, at least one vane slidably mounted in aslot in said pump stator and biased Into engagement with the outercircumferential surface of said pump rotor by fluid pressure supplied tothe slot, said pump having a pulsating action, a porting plate securedin said housing adjacent said pump assembly, a reaction motor statorsecured in said housing adjacent said porting plate, a reaction motorrotor fixed to said sleeve for rotation within said motor stator, aplurality of axially extending slots circumferentially spaced in theouter periphery of said rotor, a spring biased vane slidably received ineach of said slots and engaging the inner circumferential surface ofsaid motor stator, said reaction motor stator and rotor forming a motorassembly, a second porting plate secured in said housing adjacent saidmotor assembly, a fluid directing plate positioned on said annularflange of said end plate between said second porting plate and the endplate, means in said end plate, said fluid directing plate and saidporting plates supplying pressurized fluid from an external sourcedriving said reaction motor assembly rotating said sleeve driving saidpump assembly, the latter supplying pressurized fluid pulses to saidfluid chamber on one side of said diaphragm whereby the diaphragmresponds to inlet conditions in said pump and draws air into said airchamber through said inlet valve and responds to fluid pressurizingconditions in said pump and compresses air in said air chamberdischarging it through said exhaust valve, and a pressure relief valvein said end plate opening to bypass flow of fluid from the externalsource when the pressure of such fluid exceeds a safe operating range.